The Mount Agung volcano on the Indonesian tourist island of Bali erupted Monday evening, ejecting a 2,000-metre-high (6,560-foot-high) column of thick ash and hurling lava down its slopes.

The Indonesian geological agency’s Agung monitoring post said a loud explosion from the mountain began just after 9pm and lasted more than seven minutes.

“Flares of incandescent lava” reached 2km (1.2 miles) from the crater, it said.

It said the alert level for Agung has not been raised and the exclusion zone set up around the crater after an eruption late last year remains at 4km (2.5 miles).

Last week, Bali’s international airport closed for half a day due to volcanic ash from Agung, disrupting travel for tens of thousands.

Monday’s eruption was “strombolian”, the geological agency said, which is the mildest type of explosive volcanic eruption. It warned people living near rivers to exercise caution, particularly in wet weather, because of the risk of fast-moving flows of muddy volcanic debris.

The volcano, about 70km (45 miles) northeast of Bali’s tourist hotspot of Kuta, last had a major eruption in 1963, killing about 1,100 people.

It had a dramatic increase in activity last year, forcing the evacuation of tens of thousands of people, but had quietened by early this year. Authorities lowered its alert status from the highest level in February.

Indonesia, an archipelago of more than 250 million people, sits on the Pacific “Ring of Fire” and is prone to earthquakes and volcanic eruptions. Government seismologists monitor more than 120 active volcanoes.